Konica Minolta DiMAGE A2 Review
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Review
Date: May 24, 2004 |
Category:
Advanced Amateur - Prosumer
IMAGE QUALITY
The Konica Minolta DiMAGE A2 is a digital
camera targeted to advanced amateur photographers.
It has 8 megapixel resolution on a 16.7 mm (2/3
in.) CCD image sensor and a novel Anti-Shake Technology
that stabilizes the CCD image sensor instead of
the lens.
The Konica Minolta APO GT lens is a 28-200 mm
(35mm format equivalent) f/2.8-3.5, 7x optical
zoom. Unlike most digital cameras that have an
electronically driven zoom, Konica Minolta has
equipped the DiMAGE A2 with a mechanically linked
manual zoom that works really, really well. Those
who come from a 35mm film SLR background will
feel right at home.
We find the overall image quality of the Konica
Minolta DiMAGE A2 to be excellent.
| 7x
Optical Zoom |
 |
 |
 |
Wide-angle
7.2mm
(28mm, 35mm equivalent) |
Wide-angle
8.5mm
(33mm, 35mm equivalent) |
Telephoto
50.8mm
(200mm, 35mm equivalent) |
There are only a few digital cameras that provide
a 28mm wide-angle coverage, with most stopping
at the 35mm focal length. In the above pictures,
we show the coverage for 28mm, and then delienate
the areas covered by 33mm and 200mm. Sometimes,
that little extra coverage a 28mm lens provides
can make a noticeable difference in landscape,
real estate and interior design photography.
The 7x optical zoom reach also adds very much
to the desirabilty of this digital camera. Unlike
the other 8MP digital cameras, the Minolta GT
lens stops down to F11 (whereas the others stops
at F8). Depth of field preview is available by
turning the Function Dial to Custom and pressing
the Function button.
According to Konica Minolta, the DiMAGE A2's
Anti-Shake Technology allows hand held shots at
shutter speeds as slow as 1/25 sec. Usually the
minimum shutter speed you can safely use for camera
shake-free pictures is the reciprocal of the focal
length. So, at the maximum telephoto focal length
of 200mm, the rule of thumb is to use a shutter
speed of at least 1/200 sec. to negate camera
shake. The A2's Anti Shake Technology allows the
use of a shutter speed about 2 to 3 settings slower,
depending on the focal length used and on how
steady your hands are.
Another professional feature of the A2 that is
directly related to image quality is the ability
to record images in RAW and TIFF file formats.
It takes a long 35 sec. (from the time the red
light goes on to when it goes off) to save a RAW
image to memory card (about 50 sec. in TIFF file
format). Fortunately, the A2 has an internal buffer
and I am able to take 3 pictures in a row (either
one after the other after a slight pause or using
Continuous Shooting Mode at 1.8fps) before the
camera freezes and starts writing to memory card.
You don't have to wait for all the RAW images
to finish writing; you can shoot the next picture
after about 9 sec., and then after about every
15-17 sec.
There are two RAW modes: RAW and RAW+JPEG (where
the image is saved both in RAW file format as
well as in JPEG in the size you select). In Continuous
advance mode (1.8fps), RAW can be used. In UHS
(Ultra High Speed) continuous advance (7fps),
none of the RAW file formats can be used. In RAW+JPEG
file format, it takes about 35 sec. between shots.
It takes about 20 sec. to transfer a RAW image
from the camera to my PC, and about 25 sec, for
a RAW+JPEG image(s). Each RAW image is 3264x2448
pixels, so you definitely need a large memory
card. The camera indicates space for 20 RAW (or
15 RAW+JPEG Extra Fine, or 10 TIFF) images on
a 256MB CF card.
[The RAW file format records the image as captured
by the camera's CCD without further processing,
and allows you to precisely adjust white balance,
contrast, sharpness and saturation in an image
editing software without any loss of quality.]
| Wide-Angle Macro
vs. Telephoto Macro |
 |
 |
| Wide-Angle Macro (21 cm /
8.3 in.) |
Telephoto Macro (13 cm /
5.1 in.) |
The Macro Mode on the DiMAGE A2 is fixed at the
two extreme focal lengths. At the wide-angle 28mm
focal length, the closest distance you can get
to your subject is 21 cm (8.3 in.); at the max.
telephoto 200mm focal length, the closest distance
is 13 cm (5.1 in.), and you can move the zoom
slightly from 42.7mm to 50.8 mm.
Lest you mistakenly think this is too far to
get good detail, the above two pictures should
dispel any doubts. It is not the distance from
your subject, but the area covered (283x213mm
at wide-angle, and 52x39mm at telephoto), that
matters. In fact, there is an advantage in not
having to stick the lens right up to your subject:
you don't scare it off (assuming it's alive),
and you don't cast a shadow on it.
| Auto White Balance
Indoors |
 |
 |
| AWB |
WB = Tungsten |
As the above two pictures show, the auto white
balance tends toward the warm colours indoors
under tungsten light. Under mixed light conditions
(fluorescent + natural light), it does very well
(see the CA picture below). As expected, AWB works
flawlessly in natural light. The A2 allows you
to set a Custom White Balance with the press of
a dedicated button.
The 100% crops
above (area delimited by the white square) demonstrate
the noise at the available ISO Speeds of 64, 100,
200, 400 and 800. At ISO 64, noise is under control
though slightly visible in the images when viewed
at original size. At ISO 100 and upward, noise
becomes quite visible.
| Chromatic
Aberrations |
 |
You have to look hard to find any fault with
the image quality of the Minolta GT lens in everyday
shots. We found extremely minimal CA at the corner
delimited by the red square at top left (reproduced
at 100% crop at bottom right). In everyday shots,
CA is very hard to find. [Note: In the Minolta
DiMAGE A2 Photo Gallery, there is an indoors
shot of a Sushi Bar; the neon sign is blue/purple,
so don't go looking for evidence of CA/purple
fringing there ;o).]
| Long Shutter
Speed |
 |
50.7mm, Manual, 15 sec.,
F11, ISO 64
Tungsten WB, (Telephoto) Macro, 10 sec. Self-Timer,
Tripod Used |
The A2 allows the use of a long shutter speed
of up to 30 sec., therefore allowing night photography.
Generally, with CCD image sensors, noise usually
becomes more prominent at slow shutter speeds.
The A2 has special noise reduction algorithms
that automatically kicks in at shutter speeds
longer than 1 sec. and you'll notice a slightly
longer processing time before the next picture
can be taken.
To test this noise reduction algorithm, we decided
to take a low-light indoors shot. Let's make it
also a Telephoto Macro shot so we can more clearly
see any noise present.
At about 13cm (5.1 in.) away from the subject,
the camera lens focuses on Bamm-Bamm's eyes. Even
though we use a small aperture to maximize depth
of field, his nose still comes out blurred. For
a cheap DIY backdrop, we use a black fuzzy sweater.
Normal tungsten light bulbs from the ceiling are
the only source of illumination. We experiment
a bit to obtain the optimum exposure, eventually
settling on 15 sec. at F11. Even at this long
shutter speed, the A2's noise reduction seems
to be working great, producing a nice smooth blurring
effect of the background.
The last feature we will mention is the histogram.
The histogram can be displayed live during Recording
Mode. You can set the histogram to display permanently
by pressing the info button until the histogram
displays. The histogram is invaluable to give
an indication of under- and over-exposure (don't
rely on the LCD/EVF since the brightness is adjustable
and may be misleading).
The pictures in the Minolta DiMAGE A2 Photo
Gallery page provide a good sample of what
the Minolta DiMAGE A2 is capable of. I have provided
samples at 800x600 pixels (compressed to Quality
60/100 in Photoshop Elements).
You can safely assume that most macro shots
and slow shutter speed shots required the use
of a tripod. Any image that is adjusted for levels
in Photoshop has "_adjusted" appended
to the file name.
I have defaulted the image size to 800x600 pixels.
For those who have their monitor resolution set
to 1024x728 pixels, everything should snugly fit
and you should not have to scroll to see the whole
image. If your monitor is set to 800x600 pixels
resolution, start the slide show and then scroll
to the right to position the image within your
screen width. Then, press F11 (if you are using
Internet Explorer) to switch to full screen mode,
and the image should fill your screen nicely.
Press F11 again at any time to switch your monitor
display back to normal mode.
To return to this page from the Photo Gallery,
click on the animated graphics of the camera.
Please open and download the original size version
only if you need to and only once
to your hard drive -- and save me some precious
bandwidth. Thanks!
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